1. Field of the Invention
The invention relates to a sports boot having an upper including tightening devices so as to secure the boot on the lower portion of the user's leg, and further relates to a device for adjusting a portion of the contour of the boot to the shape of the portion of the lower leg portion the device faces, independently of the tightening devices.
2. Description of Background and Other Information
Adjustment devices of the above-mentioned type that are known in the field of ski boots, for example, are generally located on the side of the upper that is opposite the tightening devices. They improve the adaptation of the upper portion of the upper of the boot to the shape of the skier's leg and, for example, they adjust the advance angle. As the most substantial variations in the shape of the leg are in the areas of muscle mass, especially in the calves, the adjusting devices are most often implemented in the rear portion of the upper. The patent document FR 2 357 197, for example, discloses an adjusting device positioned in the rear portion of the boot upper.
This device has an upwardly open vertical recess and is made in the rear portion of the upper. A blocking device provided with a tensioning element acting on a transverse tongue or on a cable maintains the edges of the recess at a given distance that depends upon the active length of the tongue or cable. Therefore, in order to adapt to a big calf or to reduce the advance angle, the active length of the tongue or cable of the blocking device is increased. The recess edges can then move apart from one another to let the calf through or to enable the leg to somewhat straighten up, which means a diminution of the advance angle. In the latter case, the tightening devices of the upper are then tightened so that the upper always keeps the same perimeter for enveloping the lower portion of the user's leg. Conversely, to adapt the upper to a small calf or to increase the advance angle, the active length of the tongue or of the cable is reduced to cause the edges of the recess to move closer to one another and come into contact with the calf or to push the latter forward, which accentuates the advance angle. In this case, the devices for tightening the upper are loosened so that the upper always maintains the same perimeter for enveloping the lower part of the leg. This adjusting device can be functional only for use with sports boots that have a relatively flexible upper. In addition, this device is provided to be loosened after each use and requires, with each use, that the user again find, or remember, the adjustment that suits him or her.
Still by way of example, the patent document EP 371 915 discloses an adjustment device of the same type as described above, but is provided, in this case, with an articulated flap at the lower portion of the vertical recess, which it closes. In this adjustment device, the flap acts on the edges of the recess and determines the modification of the perimeter for enveloping the upper around the bottom of the leg by means of adjustable connecting elements located on the wings of the flap. Unlike the previous adjustment device, this device blocks the edges of the recess equally in the direction for moving them as well as in the direction for spacing them apart, thereby ensuring a firm support for the lower part of the user's leg, even if the direction of forces is offset with respect to the recess. However, by using a flap that is essentially articulated at the lower portion of the recess, the support surface or zone that the flap provides for the lower leg portion varies depending upon its angle of inclination. Indeed, when the flap is tilted rearward to increase the enveloping perimeter of the upper, the support surface provided is substantially equal to the total surface of the flap, which allows the spreading of forces over a large surface. However, the more the flap is forwardly inclined to reduce the enveloping area of the upper, the smaller the support surface becomes toward the upper edge of the flap. In this case, the forces of the lower leg are distributed only over a small surface, which causes painful pressure points for the user in the zone of contact with the flap. In addition, such a device requires the user to manipulate numerous small-size independent pieces, such as rods and screws, which can be challenging in a winter sports environment where one often wears gloves.